Postretirement Plans (Schedule Of Amounts Recognized In Accumulated Other Comprehensive Loss) (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	$ 26,387	$ 24,448
Prior service cost/(credit)	904	1,118
Total recognized in Accumulated other comprehensive loss	27,291	25,566
Other Postretirement Benefits Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Net actuarial loss	1,651	1,885
Prior service cost/(credit)	(799)	(1,008)
Total recognized in Accumulated other comprehensive loss	$ 852	$ 877